The present invention relates generally to portable dispensing apparatus and, more specifically, to apparatus for dispensing and mixing the components of an epoxy resin.
It is well known that many types of caulking and adhesives of various types are marketed in tubes or cartridges that require a particular type of gun or tool for use in dispensing the contents of these cartridges. The cartridges typically comprise a cylindrical tubular housing having a dispensing or discharge opening at one end and a displaceable wall at the other end. The gun or tool used with such cartridges provides a plunger that may be inserted into the tube against the displaceable wall which is moved axially to discharge the contents of the cartridge. Because of the sealing engagement required between the movable wall and the tubular housing of the cartridge and the viscous nature of the materials involved, a considerable amount of force is required to move the plunger to displace the end wall of the cartridge and dispense the contents.
The typical gun used by the homeowner to dispense caulking from a cartridge is a purely mechanical device using a type of lever and ratchet mechanism which is low in cost and reasonably adequate for the limited use to be made of it. These commonly used caulking guns have a horizontal cartridge holder with a depending handle. A manually operated lever is pulled toward the handle to operate a ratchet mechanism that ratchets forward a plunger on the free end of the plunger. However, for commercial applications or even extensive domestic applications such guns or tools prove to be unsatisfactory. Particularly in applications involving epoxy where two separate cartridges containing different constituent materials must be dispensed at the same time, the power available in the purely mechanical tools is not adequate. To obtain the force required to dispense from two cartridges at the same time, a greater mechanical advantage is needed if the tool is to be manually operated rather than relying on electrical power or compressed air.
There are many situations in the construction industry in which epoxy adhesives are used where there is no easily available supply of power for such tools. For example in road construction and road repair, there is a need to use epoxy to secure pieces of reinforcing bars together to improve the positioning of the reinforcing bars and strengthen the road after the concrete has been poured around the reinforcing bars. The use of powered tools is often impractical, requiring generators, compressors and the like, but there are currently no acceptable alternatives to the power dispensing tools.
There is a need for a simple-to-operate hydraulic caulking or dispensing gun. Preferably, the hydraulic dispensing gun would have a horizontal holder for one or more dispensing cartridges and a depending handle with a simple lever operation much like the mechanical caulking guns. Such caulking guns are very portable and can be used by workmen in awkward or tight places. The caulking gun should be relatively lightweight and relatively small so that it can be easily manipulated by a workman in a tight space or in an awkward location, to dispense the cartridge material where desired. Preferably the hydraulic caulking gun is simple in design and in operation, without a lot of hoses or parts projecting about that could become damaged or broken with rough usage at a construction site or which could interfere with the manipulation of the gun. Also, it is preferable that the hydraulic gun be relatively simple and straightforward in its manner of usage so that it may be readily employed by unskilled workmen as well as skilled workmen. Preferably, the hydraulic caulking gun should be relatively rugged and robust, thereby needing little maintenance or repair despite being subject to rough usage. The present invention is directed to providing a hydraulic caulking or dispensing apparatus that achieves one or more or all of these objectives.